Process for breaking petroleum emulsions



urally-occurring waters or Patented May 9, 1933 STATE S- PATENT OFFICE MELVIN DE GROOTE, OF ST. LOUIS, AND ARTHUR F. WIRTEL, OF WEBSTER GROVES, MISSOURI, ASSIGN'ORS TO TRETOLITE COMPANY, OF WEBSTER GROVES, MISSOURI,

A CORPORATION OF MISSOURI PROCESS FOR BREAKING- PETROLEUM EMULSIONS No Drawing.

This invention relates-to the treatment of emulsions of mineral oil and water, such as petroleum emulsions, for the purpose of separating the oil from the water.

Petroleum emulsions are of the water-inoil type, and comprise fine droplets of natbrines, dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsions. They are obtained from producing wells and from the bottom of oil storage tanks, and are commonly referred to as cut oil, roily oil, emulsified oil and bottom settlings.

The object of our invention is to provide a novel and inexpensive process for separating emulsions of the character referred to into their component parts of oil and water or brine.

Briefly described, our process consists in subjecting a petroleum emulsion of the water-in-oil type to the action of a treating agent or demulsifying agent of the kind hereinafter described, thereby causing the emulsion to break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain in a quiescent state after treatment.

The treating agent or demulsifying agent used in our process consists of or comprises a nitrogenous sulfo fatty acid in-which the nitrogen or nitrogen bearing radical, group or residue is substituted in the carboxyl or carboXyl equivalent of the fatty acid derived by combining a sulfo fatty acid with a basic nitrogen compound, such as anilin, an amino compound, an amido compound, etc., or derived by combining a nitrogenous body with a fatty body and then sulfonating the same. In other words, the nitrogen or nitrogen-bearing radical replaces the OH group of the carboxyl, or replaces the C l-1 .0 group of a fatty triglyceride with the result that the demulsifying agent may be said to contain a nitrogenous sulfo fatty acid which is to be characterized by direct linkage between the carbon of the carboxyl radical residue of the sulfo fatty acid and the nitrogen of the nitrogenous body.

As will subsequently be pointed out, the

Application. filed March 25, 1932. Serial No. 601,295.

treating agent may be used in an acidic state or after neutralization with an inorgame base to produce a salt or in the form of an ester. Therefore, the term nitrogenous sulfo fattyacid is used in the generic sense to include not only the described fatty acids as such, but also their salts and esters. The term sulfo fatty acid as employed herein is used to denote a fatty acid body in which there is present an acid sulfate group or a true sulfonic group. Such acid sulfate group or sulfonic group may be attached directly to the fatty acid radical, or it may be attached through an intervening aromatic group, as in the case of the conventional sulfo aromatic fatty acid. Sulfuric acid reacts with fatty acids as in the production of commercial Turkey-red oil, so as to produce anester of sulfuric acid, and in which there is present a HSO, group and the sulfur atom of the sulfuric acid residue is joined to the fatty group or radical through an intermediate oxygen'atom. In the production of true fatty sulfonic acids such as described in U. S. Patent No. 601,- 603 to Ernst Twitchell, dated March 29, 1898, there is present a HSO, group which is united with the fatty radical or group directly by means of the sulfur atom of the sulfonic group and not through an intervening oxygen atom (see Organic Chemis try, Norris,

to Ernst Twitchell, dated July.

2d edition, 1922, McGraw-Hill Book (10., page 365, and Industrial and Enfatty materials droxyl of the fatty acid carboxyl or. its equivalent, has been described in the literature, although their application for the particular purpose of the present invention, that is, the resolution of petroleum emulsions of the water-in-oil type, has never been disclosed or suggested. U. S. Patent 741,585, to Oscar Liebreich, dated October 13, 1903, describes derivatives of fatty acids and anilin, bases of the naphthalene series, aromatic diamines, homologues of the previously mentioned groups, and also monoalkyl derivatives of the bases mentioned and their homologues. U. S. Patent No. 746,638, to Oscar Liebreich, dated December 8, 1903, discloses the manufacture of similar materials. U. S. Patent No. 748,511, to Oscar Liebreich, dated December 29, 1903 discloses fatty compounds in which the basic nitrogenous material is meta-phenylenediamid and the like. U. S. Patent No. 1,475,477 to Carleton Ellis, November 27, 1923, describes the manufacture of similar products from oleic acid and such basic nitrogenous material as anilin,

para amido phenol, ortho toluidine, xylidine, quinoline, acetamide, diphenylamine, urea, and beta-naphthylamine. The manufacture of similar products is also disclosed in U. S. Patent No. 1,659,150 to Edward A.

Nill, dated February 14, 1928.

The treating agent or demulsifying agent used in our process consists of a product derived by reaction of a basic nitrogenous compound, such as the ones employed in the various patents previously enumerated, and a sulfo-fatty acid. They are manufactured in the same manner as the nitrogenous basic compounds described in the above mentioned patents, except that the reaction takes place between the basic nitrogenous compounds and a stable sulfo fatty acid instead of a non-sulfo fatty acid. A second general procedure for producing our treating agent is to produce the nitrogenous compound of an unsaturated fatty acid such as oleic acid or of a hydroxylated fatty acid such as ricinoleic acid, and then sulfonate the stable nitrogenous derivative of the fatty acid of the kind described in the manner emplo ed in production of Turkey red oils or sul o aromatic sulfonic acids'as employed in the commercial splitting of fats or in the manner employed in the production of true fatty sulfonic acids.

As previously stated, the'expression nitrogenous sulfo fatty acid is used in the generic sense to include also the salts and esters of the particular nitrogenous sulfo fatty acids herein described. In other words, nitrogenous sulfo fatty acids as such maybe used to constitute the treating agent of our processor they may be'neutralized prior to use with any suitable basic material such as caustic soda, caustic potash, sodium dated Leoaiae as above described may be converted into esters by conventional reaction methods with suitable alcohols, aromatic or aliphatic, and the resulting esters or ester used to constitute the treating agent of our process.

Some of the esters thus obtained may be oil soluble, and some may be water soluble. The salts such as obtained by neutralization with inorganic bases are usually water-soluble, and a few may even be water-insoluble, as in the case of aluminum.

In practising our process, we prefer to use a treating agent or a demulsifying agent obtained or produced by the following procedure: 240 pounds of anilin and 370 pounds of oleic acid are heated under a reflex condenser for 4 hours at 170 to 190 centigrade. The mixture shows considerable darkening during the reaction. When the reaction is substantially complete, it is distilled with steam to remove uncombined anilin. The resultant product should show an acid number of less than 35. This acid number is due to uncombined oleic acid. This uncombined oleic acid can be removed by washing the mixture with caustic soda, which converts the free oleic acid into water-soluble sodium oleate. Subsequent washing is required to remove any excess of alkali and the material should then be dried. The finished product should have an acid .number washings with water under conditions which do not permit the solubility of the 'nitrogenous sulfo acid. The nitrogenous sulfo fatty acid thus obtained is neutralized with strong ammonium hydroxide and employed in the form of an ammonium salt.

The specific form, state or condition of the treating agent at the time it is used or applied, to the petroleum emulsion to be treated is immaterial and may be varied to suit existing conditions. It can be used in substantially anhydrous state or in solutions of any convenient strength. A concentrated solution of the nitrogenous sulfo fatty acid can be emulsified with oil by the agency of any suitable oil soluble emulsifiers, such as calcium oleate and the resultant mixture used to constitute the treating agent of our known to have similar demulsifying prop-' erties.

In practising our process,'a treating agent or demulsifying agent of the kind above -described may be brought in contact with'the emulsion to be treated in any of the numerour ways now employed in the treatment of petroleum emulsions of the water-in-oil type with chemical demulsifying agents, such, for example, as by introducing the treating agent into the Well in which the emulsion is produced, introducing the treating agent into a conduit through which the emulsion is flowing, introducing thetreating agent into a tank in which the emulsion is stored, or introducing the treating agent into a container that holds a sludge obtained from the bottom of an oil storage tank. In some instances, it may be advisable to introduce the treating agent into a producing well in such a way that it will become mixed with water and oil that are emerging from the surrounding strata, before said Water and oil enter the barrel of the well pump or the tubing up through which said water and oil flow to the surface of the ground. After treatment the emulsion is allowed to stand in a quiescent state, usually in a settling tank, at a temperature varying from atmospheric temperature to about 200 F., so as to permit the water or brine to separate from the oil, it being preferable to keep the temperature low enough so as to prevent the valuable constituents of the oil from volatilizingl If desired, the treated emulsion may be acted upon by one or the other of various kinds of apparatus now used in the operation of breaking petroleum emulsions, such as homogenizers, hay tanks, gun barrels, filters, centrifuges, or electrical dehydrators.

The amount of treating agent on the anhydrous basis that is required to break the emulsion may vary from approximately 1 part of treating agent to 500-parts of emulsion, up to a ratio of 1 part of treating agent to 20,000 parts of emulsion, depending upon the type or kind of emulsion being treated.

In treating exceptionally refractory emulsions of the kind commonly referred to as tank bottoms or .residual pit oils, the

vminimum ratio above referred to is often maximum ratio above mentioned will frequently produce highly satisfactory results.

For the average petroleum emulsion of the water-in-oil type, a ratio of 1 part of treating agent to 5000 parts of emulsion will usually be found to produce commercially satisfactory results.

Having thus described out invention, what we claim as new and desire to secure by Letters Patent is: v

1. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the ac-' tion of a demulsifying agent containing a nitrogeneous sulfo fatty acid, characterized by direct linkage between the carbon of the carboxyl radical residue of the sulfo fatty acid and the nitrogen of the nitrogenous body.

2. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to theaction of a demulsifying agent containing a salt of a nitrogenous sulfo fatty acid, characterized by direct linkage between the carbon of the carboxyl radical residue of the sulfo fatty acid and the nitrogen of the nitrogenous body. 4

3. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a watersoluble salt of a nitrogenous sulfo fatty acid, characterized by direct linkage between the carbon of the carboxyl radical residue of the sulfo fatty acid and the nitrogen of the nitrogenous body.

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containin an ammonium salt of a nitrogenous suli o fatty acid, characterized by direct linkage between the carbon of the-carboxyl radical residue of the sulfo fatty acid and the nitrogen of the nitrogenous body.

MELVIN DE GROOTE. ARTHUR F. WIRTEL.

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